The present invention is a process for making .beta.-alkenyltrimethylsilanes and trimethylsilyl carboxylates. The process comprises contacting a mixture comprising hexamethyldisilane and an alkene carboxylate having a .beta.-unsaturated carbon atom with novel organo-palladium and organo-nickel complexes as catalysts at a temperature within a range of about 100.degree. C. to 250.degree. C. The present process is especially useful for making allyltrimethylsilane and trimethylsilyl acetate.
.beta.-Alkenyltrimethylsilanes and trimethylsilyl carboxylates are useful intermediates for introducing organofunctional silicon functionalities into silicone and organic polymers. The present method provides a method for converting hexamethyldisilane to these intermediates in near quantitative yield.
Urata et al., Bull. Chem. Soc. Jpn. 57:607-608 (1984) teach that allylic esters can react with hexamethyldisilane in the present of catalytic amounts of Pd(PPh.sub.3).sub.4, Pd{P(OPh).sub.3 }.sub.4, or RhCl(PPh.sub.3).sub.3 (Ph=phenyl) to give the corresponding allylic silanes in good yield. Urata et al. reported that P.sub.2 {P(OPh).sub.3 }.sub.4 effectively catalyzed the reaction of allyl acetate with hexamethyldisilane to give an excellent yield of .beta.-alkenyltrimethylsiloxane. However Pd (PPh.sub.3).sub.4 and RhCl (PPh.sub.3).sub.3 caused significant formation of propylene and (E)-1-propenyltrimethylsilane resulting from the double-bond migration of allyltrimethylsilane.
The present inventors have discovered novel organo-palladium and organo-nickel complexes which can serve as catalysts to effect the reaction between hexamethyldisilane and alkene acetates to form .beta.-alkenyltrimethylsilanes and trimethylsilyl carboxylates,.without the double-bond shift as described in Urata et al., supra.